haruspex's latest activity
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haruspex replied to the thread Engineering Why an Extra Coin Gives Bob a 50% Chance?.Yes, very neat, but might not be clear to all. A bit of elaboration might help… After n tosses each, - A has more heads than B with... -
haruspex replied to the thread Find the acceleration of a block (some sort of double Atwood machine?).Mostly, yes. An awkward exception is kinetic friction. When writing, say, ##\mu mg\sin(\theta)## in an equation, the sign matters and...
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haruspex replied to the thread Undergrad Why is thermal energy treated differently than other kinds of energy?.I phrased it as I did to avoid to avoid getting tangled up with the question of which way the heat flows. Otherwise it might smell like...
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haruspex replied to the thread Undergrad A high school physics problem demonstrating relative motion.Well, this is interesting. At e.g. https://en.wikipedia.org/wiki/Relative_velocity I read "The relative velocity of an object B with...
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haruspex replied to the thread Undergrad Why is thermal energy treated differently than other kinds of energy?.I don’t get the analogy. If East is defined as the side the Sun has always risen in recorded history, where a 'side' is defined by...
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haruspex replied to the thread Undergrad A high school physics problem demonstrating relative motion.The question is the speed of the fly as perceived by an observer in the carriage. We can simplify it by first making the fly stationary...
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haruspex replied to the thread Undergrad Why is thermal energy treated differently than other kinds of energy?.Clearly that is not the case. If you were to place two inert bodies in contact and observe the result that the warmer body grows warmer...
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haruspex replied to the thread Undergrad Why is thermal energy treated differently than other kinds of energy?.Not sure what Newton III has to do with energy. Please elaborate. Thermal energy is just disordered kinetic energy. Can you be more...
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haruspex replied to the thread Undergrad Is a half submerged object submerged in its own displaced water?.Revised post: As @Baluncore reminded me, ‘displacement' in this context does not have its every day meaning. The displacement of an...
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haruspex replied to the thread Undergrad Is a half submerged object submerged in its own displaced water?.Yes, my mistake… I was using displacement to mean the volume that was occupied by water and now isn’t, which is not the definition...
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haruspex replied to the thread Find the acceleration of a block (some sort of double Atwood machine?).@michelp: Further to @jbriggs444 response in post #2, it helps readers greatly if you define your variables up front, particularly in...
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haruspex replied to the thread Undergrad "Alien objects", Stillwell's "Reverse Mathematics".Isn't that dropping an axiom? I don’t see how it is 'strengthening' one. But then, going from real to complex is adding a closure...
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haruspex replied to the thread Undergrad Why is water pressure increased in a plastic bag in a bucket?.Certainly in the videos corresponding to case D that is true, but it is not clear to me whether it applies in any actual experiment that...
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haruspex replied to the thread Undergrad Why is water pressure increased in a plastic bag in a bucket?.That's one of the only two ideas I had. The video shows the water being poured over the top, but there could still be dry patches...
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haruspex replied to the thread Vector calculus: line element dr in cylindrical coordinates.@deananderson , Just in case it is still not clear from the various responses above, they can be synthesised as: ##\vec...